2011 INFINITI QX56 brake

SYSTEMSBC-7
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SYSTEM
PRE-CRASH SEAT BELT SYSTEM
PRE-CRASH SEAT BELT SYSTEM : System DiagramINFOID:0000000006237877
PRE-CRASH SEAT BELT SYSTEM : System DescriptionINFOID:0000000006237878
 Pre-crash seat belt system integrates control unit and motor in driver and passenger seat belt retractors.
 Provides a sense of ease when pre-crash seat belt c ontrol unit judges the emergency braking operation, the
intelligent brake assistance operating status, the c ontinuous ABS operating status, the emergency steering
wheel operation, the excessive vehicle inclination stat us, or the lateral slippage status during cornering.
The motor immediately retracts the seat belt and suppresses change in occupant posture.
 Even in a situation where a collision is unavoidable, effe cts of other safety devices, like the air bag, are max-
imized and damages are reduced.
 Motor retracts seat belt when unfastening and extrac ts seat belt when fastening to reduce the feeling of
pressure. (comfort function)
FUNCTION DESCRIPTION
Pre-crash seat belt system operat es under the following conditions.
 During emergency brake operation
 When ABS continuously operates
 When intelligent brake assistance operates
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
JMHIA1565GB
Revision: 2010 May2011 QX56

SBC-8
< SYSTEM DESCRIPTION >
SYSTEM
 When the vehicle inclined excessively
 When comfort function operates
OPERATION CONDITION
Operation while driving
 Operation start and stop conditions of pre-crash seat belt system are as shown in the following table.
 The activation and deactivation conditions of pre-crush seat belt are as per the following.
NOTE:
For details of intelligent brake assist system.Refer to BRC-152, "
INTELLIGENT BRAKE ASSIST : System
Description".
Comfort function
 Seat belt is retracted and the looseness is reduced in the state as shown in the following table.
 Operation start and stop conditions of pre-crash seat belt system are as shown in the following table.
Operation Prohibition Condition
Pre-crash seat belt system does not operate in the following conditions.
 When seat belt is not fastened (only the seat belt that is not fastened does not operate)
 When motor is overheat due to contentious operation*1
 When the system is in fail-safe mode *1: System operation is temporarily deactivated to av oid overheating, when comfort function is continuously
operated (18 times or more) during a short period of time by fastening and unfastening seat belts or opening
and closing doors.
MALFUNCTION WARNING
When system malfunction is detected, comfort function is deactivated to warn customer of system malfunc-
tion.
Operation item Operation start condition Operation stop condition
During emergency brake operation  Vehicle speed is 15 km/h (9 MPH) or more
 Emergency braking status is detected
 During acceleration
 When stopped
When ABS continuously operates  ABS continuously operates for 2 seconds or
more
 Brake pedal is in depressed state
When intelligent brake assistance oper-
ates System detects that intelligent brake assistance is
in operating status
2 seconds after operation start
When lateral slippage during cornering
occurs  Vehicle speed is 30 km/h (19 MPH) or more
 System detects that the vehicle is in lateral slip-
page state
 System detects that the vehicle is driving on a curve  Vehicle stopped
 1 second or more after maintaining
steering wheel angle in straight driv-
ing state
When steering wheel is rotated for emer-
gency  Vehicle speed is 60 km/h (36 MPH) or more
 Steering wheel angle is 90 degrees or more
 System detects that steering wheel is rotated for
emergency
When the vehicle inclined excessively  Vehicle speed is 30 km/h (19 MPH) or more
 System detects that the vehicle inclined exces-
sively  During acceleration
 Vehicle stopped
Operation item Activating condition Deactivating condition
Door open  Seat belt is in not fastened state
 Door is operated to open from closed
 Vehicle stopped  Seat belt retract is complete
 13 seconds after start retracting
Seat belt is fastened  When door is closed
 Seat belt is fastened  Seat belt is unfastened
 1 second after operation
Seat belt is release Seat belt is unfastened  Seat belt retract is complete
 10 seconds after start retracting
Revision: 2010 May2011 QX56

SYSTEMSBC-9
< SYSTEM DESCRIPTION >
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PRE-CRASH SEAT BELT SYSTEM : Fail SafeINFOID:0000000006237879
 When a system malfunction is detected, deactivates a part of the system or all functions depending on the
malfunctioning part.
 When the malfunction condition recovers to the norma l condition, the system returns to the normal opera-
tion.
*1: The deactivation mode differs depending on the internal malfunctioning condition of control unit Display contents of CONSULT-III Fail-safe
U0126 STRG ANG SEN SIG Stops the operation in the conditions as per the following.
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 A part of comfort function
U0428 STRG ANGL CAL Stops the operation in the conditions as per the following.
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 A part of comfort function
U1000 CAN communication circuit Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2451 SEAT BLT MTR DR CIRC Fully deactivates the whole operation.
B2452 SEAT BLT MTR AS CIRC Deactivate s a part of comfort function.
B2453 BR_STROKE_SEN_CIRC Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuously operates
 A part of comfort function
B2454 SEAT BLT PWR DR CIRC Fully deactivates the whole operation.
B2455 CONTROL UNIT DR Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2456 SEAT BLT PWR AS Deactivates a part of comfort function.
B2457 CONTROL UNIT AS Deactivates a part of comfort function.
B2458 LOCAL COMM Deactivates a part of comfort function.
B2461 VHCL SPEED SIGNAL Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 When comfort function operates
B2463 ROLLOVER SIGNAL Stops the operation in the conditions as per the following.
 When the vehicle inclined excessively
 A part or the whole comfort function
B2466 DR/AS CONTROL UNIT Deactivates a part of comfort function.
B2470 SYS HEAT PROTC DR  Fully deactivates the whole operation.
 Operation return
- 1 time operation becomes possible after approximately 30 seconds
- Returns to the initial condition after approximately 8 minutes
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (PRE-CRASH SEAT BELT)SBC-11
< SYSTEM DESCRIPTION >
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DIAGNOSIS SYSTEM (P RE-CRASH SEAT BELT)
CONSULT-III FunctionINFOID:0000000006237882
Diagnosis for pre-crash seat belt syst em can be performed using CONSULT-III.
APPLICATION ITEM
SELF-DIAGNOSIS RESULTS
Refer to SBC-16, "DTC Index".
CAUTION:
When malfunctions are detect ed in several systems, includin g CAN communication [U1000], trouble-
shoot CAN communication [U1000].
A malfunction of system may be disp layed when battery voltage is low (when 7 to 8 V is continued for
approximately 2 seconds) even though the system is not malfunctioning. Erase DTC memory and
never replace any parts after making sure that the syst em is normal, especially if the malfunctions are
displayed after replacing battery.
ERASING SELF-DIAGNOSIS RESULTS
 SELF-DIAGNOSIS RESULTS Current “SELF-DIAG RESULTS” are displayed. (If all suspect circuits have been repaired, “NO DTC” is dis-
played.)
DATA MONITOR
Part to be diagnosed Diagnosis Mode Function description
Pre-crash seat belt Self-diagnosis Results
 Displays data recorded when a malfunction is de-
tected.
 Erases DTC recorded in memory.
Data Monitor Displays input data for pre-crash seat belt control
unit in real time.
Work Support Changes the setting for each system function.
CAN DIAG SUPPORT MNTR Monitors communication status of CAN communi-
cation.
Ecu Identification Displays pre-crash seat belt control unit part num-
ber.
Monitor item Contents
BUCKLE SW RH Indicates [ON/OFF] condition of seat belt buckle switch (RH).
BUCKLE SW LH Indicates [ON/OFF] condition of seat belt buckle switch (LH).
VEHICLE DISTANCE Indicates [ON/OFF] condit ion of intelligent brake assist signal.
IGN SW Indicates [ON/OFF] condition of ignition switch.
FR DOOR SW RH Indicates [Close/Open] condition of front door switch (RH).
FR DOOR SW LH Indicates [Close/Open] condition of front door switch (LH).
ABS ACTIVATING Indicates [ON/OFF] co ndition of ABS operation signal.
VHCL SPEED Indicates [Km/h] vehicle speed signal.
BRK PEDAL SNSR1 Indicates [V] voltage of brake pedal stroke sensor 1 signal.
BRK PEDAL SNSR2 Indicates [V] voltage of brake pedal stroke sensor 2 signal.
STRG ANGLE Indicates [deg] steering angle signal.
STRG ANGLE SPEED Indicates [deg/s] steering angle speed signal.
INCLINATION JDMT Indicates [ON/OFF] condition of pre roll over signal.
PRE-TEN ACTIVTN Indicates [ON/OFF] condition of pre-tensioner operated signal.
HEAT PROTC RH Indicates [ON/OFF] condition of heat protection (RH).
HEAT PROTC LH Indicates [ON/OFF] condition of heat protection (LH).
Revision: 2010 May2011 QX56

PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)SBC-13
< ECU DIAGNOSIS INFORMATION >
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ECU DIAGNOSIS INFORMATION
PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)
Reference ValueINFOID:0000000006237883
VALUES ON THE DIAGNOSIS TOOL
CONSULT-III MONITOR ITEM
Monitor item Condition Value/Status
(Approx.)
BUCKLE SW RH RH seat belt is not fastened OFF
RH seat belt is fastened ON
BUCKLE SW LH RH seat belt is not fastened OFF
RH seat belt is fastened ON
VEHICLE DISTANCE Not activated OFF
Activated ON
IGN SW Ignition switch OFF OFF
Ignition switch ON ON
FR DOOR SW RH LH door close CLOSE
LH door open OPEN
FR DOOR SW LH RH door close CLOSE
RH door open OPEN
ABS ACTIVATING ABS is inactive OFF
ABS is active ON
VHCL SPEED While driving Equival ent speedometer reading (km/h)
BRK PEDAL SNSR1 Brake released → depressed (1 V → 4 V)
BRK PEDAL SNSR2 Brake released → depressed (4 V → 1 V)
STRG ANGLE Steering wheel: 0
° (Neutral) ±2.5 (deg)
Steering wheel: 90 ° (Turned right) +90 (deg)
Steering wheel: 90 ° (Turned left) -90 (deg)
STRG ANGLE SPEED Steering wheel: Being turnedDepending on steering acceleration speed
(deg/s)
INCLINATION JDMT Vehicle is level OFF
Vehicle is inclined ON
PRE-TEN ACTIVTN Seat belt pre-tensioner is not activated OFF
Seat belt pre-tensioner is activated ON
HEAT PROTC RH RH heat protection is not activated OFF
RH heat protection is activated ON
HEAT PROTC LH LH heat protection is not activated OFF
LH heat protection is activated ON
Revision: 2010 May2011 QX56

SBC-14
< ECU DIAGNOSIS INFORMATION >
PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)
TERMINAL LAYOUT
PHYSICAL VALUES
Fail SafeINFOID:0000000006237884
 When a system malfunction is detected, deactivates a part of the system or all functions depending on the
malfunctioning part.
 When the malfunction condition recovers to the normal condition, the system returns to the normal opera-
tion.
JMHIA0711ZZ
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
1
(Y) Ground Power supply Input — Battery voltage
2
(G) Ground Brake pedal stroke sensor signal 1 Input Brake released
→ depressed 1 V - 4 V
4
(P) Ground CAN-L Input/
Output ——
6
(LG/R) Ground Seat belt buckle switch signal Input Seat belt is fastened 0 V
Seat belt is unfastened 5 V
8
(G) Ground Local Communication Line 2 Output IGN ON 5 V
9
(–) Ground Shield — — —
10
(R) Ground Brake pedal stroke sensor power circuit Output IGN ON 5 V
12
(B) Ground Brake pedal stroke sensor signal 2 Input Brake released
→ depressed 4 V - 1 V
14
(L) Ground CAN-H Input/
Output ——
16
(W) Ground Local Communication Line 1 Input/
Output ——
17
(W) Ground Brake pedal stroke sensor ground circuit — — 0 V
18
(B) Ground Ground — — 0 V
19
(W) Ground Motor drive circuit power supply Input — Battery voltage
20
(B) Ground Motor drive circuit ground — — 0 V
Revision: 2010 May2011 QX56

PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)SBC-15
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*1: The deactivation mode differs depending on the internal malfunctioning condition of control unit Display contents of CONSULT-III Fail-safe
U0126 STRG ANG SEN SIG Stops the operation in the conditions as per the following.
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 A part of comfort function
U0428 STRG ANGL CAL Stops the operation in the conditions as per the following.
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 A part of comfort function
U1000 CAN communication circuit Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2451 SEAT BLT MTR DR CIRC Fully deactivates the whole operation.
B2452 SEAT BLT MTR AS CIRC Deactivate s a part of comfort function.
B2453 BR_STROKE_SEN_CIRC Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuously operates
 A part of comfort function
B2454 SEAT BLT PWR DR CIRC Fully deactivates the whole operation.
B2455 CONTROL UNIT DR Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2456 SEAT BLT PWR AS Deactivates a part of comfort function.
B2457 CONTROL UNIT AS Deactivates a part of comfort function.
B2458 LOCAL COMM Deactivates a part of comfort function.
B2461 VHCL SPEED SIGNAL Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuously operates
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 When comfort function operates
B2463 ROLLOVER SIGNAL Stops the operation in the conditions as per the following.
 When the vehicle inclined excessively
 A part or the whole comfort function
B2466 DR/AS CONTROL UNIT Deactivates a part of comfort function.
B2470 SYS HEAT PROTC DR  Fully deactivates the whole operation.
 Operation return
- 1 time operation becomes possible after approximately 30 seconds
- Returns to the initial condition after approximately 8 minutes
Revision: 2010 May2011 QX56

SBC-16
< ECU DIAGNOSIS INFORMATION >
PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE)
DTC Index
INFOID:0000000006237885
DTC Trouble diagnosis name
(CONSULT-III display) DTC detection condition Reference
U0126 STRG ANG SEN SIG Steering angle sensor malfunction is received SBC-33
U0428 STRG ANGL CAL Steering angle sensor calibration incomplete signal is receivedSBC-34
U1000 CAN COMM CIRCUITPre-crash seat belt control unit cannot transmit and receive CAN
communication signal for 2 seconds or more SBC-35
B2451 SEAT BLT MTR DR CIRC Motor or control unit malfunction
 Seat belt motor circuit is open or shorted
SBC-36
B2452 SEAT BLT MTR AS CIRC Motor or control unit malfunction
 Seat belt motor circuit is open or shorted SBC-37
B2453 BR_STROKE_SEN_CIRC
 Brake pedal stroke sensor malfunction
 Brake pedal stroke sensor circuit is open or shorted SBC-38
B2454 SEAT BLT PWR DR CIRC Motor power su
pply circuit is open or shortedSBC-41
B2455 CONTROL UNIT DR Malfunction in pre-crash seat belt control unit SBC-42
B2456 SEAT BLT PWR AS CIRC Motor power supply circuit is open or shortedSBC-43
B2457 CONTROL UNIT AS Malfunction in pre-crash seat belt control unit SBC-44
B2458 LOCAL COMM Local communication line open or shortedSBC-45
B2461 VHCL SPEED SIGNAL Vehicle speed signal malfunction is received SBC-47
B2463 ROLLOVER SIGNAL Rollover signal malfunction is received SBC-48
B2466 DR/AS CONTROL UNIT Control unit is out of the vehicle specificationSBC-49
B2470 SYS HEAT PROTC DRDeactivation for cooling to prevent system heating due to continuous
operation SBC-50
B2471 SYS HEAT PROTC ASDeactivation for cooling to prevent system heating due to continuous
operation
SBC-51
Revision: 2010 May2011 QX56